The IEEE 802.11 standard at the time of this filing outlines two mechanisms to provide timing synchronization for stations. In an infrastructure mode of operation, an access point (AP) is the timing master of the basic service set (BSS), and stations always accept the timing synchronization information of the beacon transmitted by the AP. However in independent basic service set (IBSS) mode of operation, the timing synchronization function (TSF) is performed by all stations in a distributed manner and stations in an IBSS adopt the timing received from any beacon or probe response that has a TSF value later than its own TSF timer.
The diversity of devices available in mesh creates an interesting challenge of synchronization and beacon generation because it is difficult to do a strict classification of some mesh devices. While a wireless local area network (WLAN) mesh is expected to reuse the concepts from BSS based AP beaconing and IBSS station beaconing, special attention needs to be given for devices like a mesh point (MP), which may be a wireless device containing an 802.11-conformant MAC and PHY interface to the wireless medium that provides mesh services, and a mesh access point (MAP), which is a MP that is also an access point, and therefore supports both BSS and mesh interface functions. Beacon collisions between multiple MAPs, packet forwarding in presence of power save (PS) MPs are among few areas which need to be addressed.